Decentralized Anonymous IoT Data Sharing with Key-Private Proxy Re-Encryption

Secure and scalable data sharing is one of the main concerns of the Internet of Things (IoT) ecosystem. In this paper, we introduce a novel blockchain-based data-sharing construction designed to ensure full anonymity for both the users and the data. To share the encrypted IoT data stored on the cloud, users generate tokens, prove their ownership using zk-SNARKs, and target the destination address anonymously. To tackle the privacy concerns arising from uploading the data to the cloud, we use key-private re-encryption and share only the necessary information with the proxy. As the first time in the literature, we have integrated a token-based blockchain and a key private proxy re-encryption to achieve a fully anonymous data sharing scheme. Furthermore, we provide security proof of our proposed scheme is secure against existential forgery under chosen-plaintext attacks, under eDBDH assumption in the random oracle model.